title: Real-time integration of 2D intracardiac echocardiography and 3D electroanatomical mapping to guide ventricular tachycardia ablation.
abstract: BACKGROUND
  Ablation of left ventricular tachycardia (LV VT) involves point-by-point reconstruction of the three-dimensional (3D) virtual anatomy. It is time consuming and requires substantial fluoroscopy exposure. Two-dimensional (2D) intracardiac echocardiography (ICE) affords real-time imaging of the cardiac structures.
  
  
  OBJECTIVE
  This study sought to evaluate a mapping system integrating ICE with 3D mapping to guide VT ablation.
  
  
  METHODS
  Seventeen patients (16 men, 62 +/- 11 years, LV ejection fraction 40% +/- 15%) had ablation of nonidiopathic VT guided using a system integrating 3D mapping and ICE. ICE probe with a location sensor tracked by the mapping system was positioned in the right heart. Endocardial contours traced on gated images of the LV were used to generate a registered 3D map. Regional wall motion abnormalities (WMA) were tagged.
  
  
  RESULTS
  3D maps were created in 26 +/- 8 min, before entering the LV and without fluoroscopy. Maps were built from 23 +/- 7 contours. Regional WMA corresponded to low bipolar voltage (<0.5 mV). Procedure time was 240 +/- 77 min, with fluoroscopy time of 25 +/- 12 min. LV volume by ICE was 172 +/- 119 cm(3) versus 164 +/- 112 cm(3) for the point-by-point maps (P = .5). Scar area by ICE was 33 +/- 32 cm(2) versus 36 +/- 33 cm(2) for voltage mapping (P = .4). At 5 +/- 4 months, 12 patients (71%) were free of VT.
  
  
  CONCLUSIONS
  A system combining 2D ICE and 3D mapping can reconstruct a 3D shell of the LV, including a substrate map based on regional WMA without the need to enter the LV. VT ablation guided using this approach is safe and effective.
authors.affiliation: Southlake Regional Health Center, Newmarket, Ontario, Canada. y.khaykin@utoronto.ca
authors.forename: Yaariv
authors.initials: Y
authors.lastname: Khaykin
authors.forename: Allan
authors.initials: A
authors.lastname: Skanes
authors.forename: Bonnie
authors.initials: B
authors.lastname: Whaley
authors.forename: Carol
authors.initials: C
authors.lastname: Hill
authors.forename: Marianne
authors.initials: M
authors.lastname: Beardsall
authors.forename: Catherine
authors.initials: C
authors.lastname: Seabrook
authors.forename: Zaev
authors.initials: Z
authors.lastname: Wulffhart
authors.forename: Richard
authors.initials: R
authors.lastname: Oosthuizen
authors.forename: Lorne
authors.initials: L
authors.lastname: Gula
authors.forename: Atul
authors.initials: A
authors.lastname: Verma
mesh_terms: D000368:Aged; D018780:Body Surface Potential Mapping; D017115:Catheter Ablation; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors